I can see why they say that. I visited both a Boost and a Sprint store and with the IMEI and MEID numbers it shows not eligible or compatible if you try to swap it or even if you sign up for new service with Sprint , if you are activating it as a new service for some reason on Boost their system accepts it. Just go as far as putting in the IMEI and SIM card data and cancel and it then will work. They can't even put it in their form to see what SIM card they need to use to have it on Sprint/Boost without first getting it into their system somehow to be accepted. They're just repeating what their system tells them they just don't know their system seems to be broken.
That's why I will be leaving Boost. Just to much crap. To many different answers depending what store you go to.
They've taken most of the phones out of most of the stores so you can't even see or feel what you think you might want.
Just totally over it and then locking you in for 12 months which no other carrier does anymore if you own your phone outright.
It's in the fine print. They are not transparent about it. It doesn't make any difference whether you own the phone outright to them. My phone was purchased directly from Samsung it is CDMA and GSM compatible. UNLOCKED.You can find it on their policy online. Al the carriers at one time did it, all but Sprint and Boost relaxed that stipulation unless you have a contracted phone with them.
That's the same card number Boost used in my S10e. I had to go to a different store as the one around the corner from me didn't have it. So she called another store and they had it.